[JB in AZ]

Here's one place to look: AVAS For your reading pleasure

 

[JB in AZ]

Here is someone that hacked theirs to make engine sounds.

This is just AWFUL!

 

[JB in AZ]

...
There is nothing "official" you can do, short of buying a UK model that has a switch. You might have to get used to driving from the wrong side though.

You will also think you are getting MUCH better fuel economy...